KR20130091016A

KR20130091016A - Sensing magnet apparatus for eps motor

Info

Publication number: KR20130091016A
Application number: KR1020120012208A
Authority: KR
Inventors: 김정근
Original assignee: 엘지이노텍 주식회사
Priority date: 2012-02-07
Filing date: 2012-02-07
Publication date: 2013-08-16

Abstract

The sensing magnet of the motor according to the present invention includes a disk-shaped plate in which a rotating shaft is inserted in the center; A ring-shaped sensing magnet in which the plate is inserted into a mold and integrally injection-molded with the plate, a main magnet is formed at a position close to an outer circumferential surface, and a sub magnet is formed at a position close to the through hole; And a plurality of through holes formed through the plate, wherein the sensing magnets are disposed to be concentric with each of the inner diameter and the outer diameter of the plate, and are formed to fill the inside of the through hole through an injection process. It is characterized by.

Description

SENSING MAGNET APPARATUS FOR EPS MOTOR}

The present invention relates to a sensing magnet assembly of a motor.

In general, a steering device assisted by a separate power is used as a device to ensure the stability of steering of the vehicle. Conventionally, such an auxiliary steering device is used as a device using hydraulic pressure, but recently, an electric power steering system (Electronic Power Steering System) having low power loss and high accuracy is used.

The electric steering device (EPS) as described above drives the motor in an electronic control unit (ECU) according to the driving conditions sensed by the vehicle speed sensor, torque angle sensor, torque sensor, etc. to ensure turning stability and provide fast resilience. This allows the driver to drive safely.

In this EPS system, the motor assists the driver to operate the steering wheel for steering, so that the steering operation can be performed with less force. The motor uses a BLDC motor.

In general, the BLDC motor is coupled to the housing and the cover member to form an exterior of the motor, and a stator is provided on an inner circumferential surface of the housing, and the center of the stator is rotatable according to electromagnetic interaction with the stator. A rotor to be installed is provided. The rotor is rotatably supported by a rotating shaft, and a steering shaft of the vehicle is connected to an upper portion of the rotating shaft to provide power to assist steering as described above.

On the other hand, the inside of the cover member is provided with a printed circuit board mounted with a sensing sensor provided with a magnetic element, the sensing sensor detects the magnetic force of the sensing magnet installed to be rotationally interlocked with the rotor, the current position of the rotor Make it understandable. In general, the sensing magnet is fixed to the upper side of the plate installed on the upper side of the rotor using an adhesive. When the sensing magnet is magnetized to the plate, the position of the rotor can be detected by coupling the plate to the rotating shaft in accordance with the magnetic field direction.

By the way, the plate and the sensing magnet is bonded using an adhesive as described above. Therefore, it is difficult to accurately manage the bonding process and there is a possibility of detachment of the sensing magnet. In particular, because of the characteristics of the vehicle that the environmental conditions vary, the bonding relationship must be maintained only by the adhesive force of the adhesive itself, so if the motor is used while exchanging the high temperature state and the low temperature state, or exposed to a high temperature state for a long time, the adhesive force of the adhesive falls. In addition, the sensing magnet may be dislodged or the motor may not be driven. Such a structure may require more detailed work of the adhesive application process, as well as the difficulty of selecting the adhesive and the economic problem of using an expensive adhesive.

In addition, when the adhesive is applied to the surface of the flat sensing magnet, when the adhesive is applied too much when the plate and the sensing magnet, the adhesive applied to the surface of the sensing magnet may leak out of the adhesive site In addition, the thickness of the adhesive layer is excessively formed, so that the sensing magnet and the Hall element may be disposed too close or may interfere with each other.

In particular, when a large pressure is applied in the pressing process of pressing the sensing magnet to match the thickness, there is a problem that the sensing magnet may be broken.

The present invention improves the coupling structure between the sensing magnet and the plate, even if used in a high temperature state for a long time, or even when used in environmental conditions with severe temperature changes, the sensing magnet of the motor improved structure so that there is no need to worry about the departure of the sensing magnet The purpose is to provide.

The plate is preferably formed of a metal material.

The through-holes are preferably formed through at regular intervals at a position close to the outer peripheral surface of the plate.

In addition, the through hole may be formed through the plate in the shape of any one of a circle, a triangle, a polygon.

The sensing magnet is preferably formed to surround at least one side of the plate.

The plate may be formed to a size smaller than the diameter of the sensing magnet.

Sensing magnet assembly of the motor according to another embodiment of the present invention, the disk-shaped plate is inserted into the rotation axis in the center; A ring-shaped sensing magnet in which the plate is inserted into a mold and integrally injection-molded with the plate, a main magnet is formed at a position close to an outer circumferential surface, and a sub magnet is formed at a position close to the through hole; And a sawtooth uneven structure formed on the circumferential surface of the plate, wherein the sensing magnet is in surface contact with the sawtooth uneven structure through an injection process.

In this case, the plate is formed of a metal material, it is preferable that the uneven structure is formed on the outer peripheral surface of the plate at regular intervals.

In addition, the plate is preferably formed in a size smaller than the diameter of the sensing magnet.

According to another embodiment of the present invention, the plate may further include a plurality of through-holes formed at regular intervals adjacent to the outer circumferential surface. In this case, the ratio of the number of teeth forming the through hole and the uneven structure may be provided as 1: 2.

According to the present invention as described above, since the sensing magnet is formed on the plate through the insert molding without using the adhesive, the plate and the magnet are separated while the adhesive strength of the adhesive is reduced by high-speed rotation, long-term use, or use at a high temperature. Can be prevented.

In addition, it is possible to produce the plate and the sensing magnet as a single part, without the need for an assembly equipment for bonding the sensing magnet and the plate using an adhesive, thereby reducing manufacturing costs and simplifying the assembly process. can do.

1 is a schematic cross-sectional view of an EPS motor according to an embodiment of the present invention;
2 is a plan view illustrating a sensing magnet according to a first embodiment of the present invention;
3 is a plan view showing a sensing magnet according to a second embodiment of the present invention, and
4 is a plan view illustrating a sensing magnet according to a third exemplary embodiment of the present invention.

Hereinafter, a sensing magnet assembly of a motor according to a preferred embodiment of the present invention will be described with reference to the drawings.

1 is a schematic cross-sectional view of an EPS motor according to a preferred embodiment of the present invention, Figure 2 is a plan view showing a sensing magnet according to a first embodiment of the present invention, Figure 3 is a second embodiment of the present invention. 4 is a plan view illustrating a sensing magnet, and FIG. 4 is a plan view illustrating a sensing magnet according to a third exemplary embodiment of the present invention.

As shown in FIG. 1, as shown, the EPS motor according to the present invention includes a housing 1 and a cover member (not shown) coupled to an upper side of the housing 1, and the combination thereof. Through this, the appearance of the motor is formed.

A bracket 2 for fixing is provided on the side of the housing 1, and a stator 4 around which a plurality of coils are wound is provided on an inner circumferential surface thereof, and a rotor 5 is rotated in the center of the stator 4. It is rotatably installed by (3). The rotor 5 may be configured by a magnet coupled to the rotor core, and in some cases, the rotor core and the magnet may be integrally formed.

On the upper side of the rotor 5, a sensing magnet 7 for obtaining position information of the rotor 5 is coupled to the plate 6 and installed.

Disc plate 6a according to the first embodiment of the present invention, as shown in Figure 1 and 2, is provided in a disk shape, it can be coupled by the rotating shaft 3 and the fastening member 10. . The disk plate 6a is preferably formed of a metal material.

The disk plate 6a is first disposed in a mold when the sensing magnet 7 is sintered and / or formed in molding, so that the disk plate 6a becomes a core and is integrally injected together with the sensing magnet 7. Can be molded.

The sensing magnet 7 is provided in a disk shape having a diameter larger than the diameter of the disk plate 6a, and a through hole having a predetermined diameter is formed in the center thereof, and the rotating shaft 3 fixed to the disk plate 6a is provided. It can be configured to pass through. The main magnet M1 may be provided at a position close to the outer circumferential surface of the sensing magnet 7, and the sub magnet M2 may be provided at a position close to the through hole. Although not shown on the upper side of the sensing magnet 7, a magnetic element such as a Hall IC is mounted on the printed circuit board fixed to the inner surface of the cover member so as to face the sensing magnet 7. The rotation of the sensing magnet 7 can be detected.

On the other hand, as shown in Figure 1, the sensing magnet 7 may be configured to surround at least one surface of the disk plate (6a), if necessary, to surround the entire disk plate (6a) It can also be configured. However, since the sensing magnet 7 has the greatest influence of the centrifugal force acting in the circumferential direction at the center of the disk-shaped body according to the rotation of the motor, the sensing magnet 7 does not necessarily need to be formed so that the plate 6 becomes a core. It is sufficient to be formed to achieve.

The present invention is characterized by insert injection molding the disc plate 6a and the sensing magnet 7 into a single body, thereby simplifying the assembly process according to the number of parts and reducing the parts production cost.

In addition, in order to more firmly maintain the coupling between the disk plate 6a and the sensing magnet 7, as shown in FIG. 2, a plurality of through holes 100 are provided in the disk plate 6a at regular intervals. Can be formed through. According to a first preferred embodiment of the present invention, the through holes 100 may be formed through about eight at the same interval, but the present invention is not limited thereto, and according to the size of the disc plate 6a, the through holes may be formed. The number of balls 100 may increase or decrease.

The through holes 100 may be formed in a circular shape as shown in FIG. 2, but are not limited thereto, and may be formed in a triangle, a square, a polygon, an ellipse, and the like as necessary. When the disc plate 6a is formed of a metal material, the through holes 100 may be simply configured by using a press working or the like.

When the through-hole 100 is sintered and / or injection-molded the sensing magnet 7, after the materials constituting the sensing magnet 7 pass through the through-hole 100 and are molded, sensing The coupling between the magnet 7 and the disc plate 6a can be held firmly.

On the other hand, as shown in the through hole 100, it is preferable that the through hole is formed in a portion adjacent to the outer circumferential surface of the disk plate 6a, which is the disk plate 6a and the sensing magnet 7 is a disk shape, Since it rotates in conjunction with the rotation of the motor, the centrifugal force is formed at the end of the circumferential portion that acts greatly, so as to provide a tighter bonding force.

According to the second embodiment of the present invention, in place of the through-hole 100 of the first embodiment, as shown in FIG. 3 on the outer circumferential surface, the tooth plate 6b having the serrated uneven structure 200 is provided. ) May be provided. According to the tooth plate 6b having the concave-convex structure 200, the area in which the tooth plate 6b and the sensing magnet 7 mesh with each other on the outer circumferential surface becomes wider, and thus, the strengthening of the bonding force may be expected due to the increase in the contact area. have.

On the other hand, the number of teeth constituting the uneven structure 200 needs to be appropriately provided. If the number of teeth is too large, the contact area may be wider, but the rigidity of each tooth may be reduced, on the contrary, if the number of teeth is too small, there is no significant effect on the increase of the bonding force according to the increase in area. According to a preferred embodiment of the present invention, the teeth constituting the uneven structure 200 is preferably formed more than the number of through holes 100 configured in the first embodiment, for example the tooth plate 6b It is also possible to provide a total of 16 based on the center of the).

According to the third embodiment of the present invention, it may be configured to have both the structures of the first and second embodiments described above. That is, the through hole 100 may be formed at a position close to the outer circumferential surface, and the hybrid plate 6c including the sawtooth-shaped uneven structure 200 may be formed at the outer circumferential surface. In this case, there is no fear that the sensing magnet 7 and the hybrid plate 6c are separated from the motor rotating at high speed.

The teeth forming the through hole 100 and the uneven structure 200 may be formed to have a predetermined ratio. According to an embodiment of the present invention, the through hole 100 and the uneven structure 200 may be formed. The number of teeth to be formed may be formed in a ratio of 1: 2.

According to the present invention as described above, since it does not perform the chemical fixation by the adhesive as in the prior art, even if used for a long time in a high temperature and / or low temperature state, according to the weakening of the adhesive force according to the physical and chemical properties of the adhesive, the sensing magnet ( 7) does not occur the defect that is caused by separating from the motor.

In addition, since the bonding process of the sensing magnet 7 using the adhesive can be omitted, the assembling process can be simplified, and the trouble of using expensive adhesives can be eliminated according to the motor driving conditions.

On the other hand, the above has been described as an example of an EPS motor, but not limited to this, any motor structure having a sensing magnet (7) can be applied to any motor if necessary.

In the foregoing, the present invention has been described in detail based on the embodiments and the accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the content of the following claims.

One; Motor housing 2; The cover member
3; Axis of rotation 4; The stator
5; Rotor 6a; Disc plate
6b; Tooth plate 6c; Hybrid plate
7; Sensing magnet 8; Printed circuit board
9; Magnetic element 20; Holder member
100; Through hole 200; Uneven structure

Claims

A disk-shaped plate into which a rotation shaft is inserted in the center;
A ring-shaped sensing magnet in which the plate is inserted into a mold and integrally injection-molded with the plate, a main magnet is formed at a position close to an outer circumferential surface, and a sub magnet is formed at a position close to the through hole; And
And a plurality of through holes formed through the plate.
The sensing magnet is disposed so that the inner diameter and the outer diameter of the plate and each of the concentric, the sensing magnet assembly of the motor is formed to fill the inside of the through hole through the injection process.

The method of claim 1, wherein the plate,
Sensing magnet assembly of the motor formed of a metal material.

The method of claim 1, wherein the through hole,
Sensing magnet assembly of the motor is formed through a predetermined interval at a position close to the outer peripheral surface of the plate.

The method of claim 1, wherein the through hole,
Sensing magnet assembly of the motor is formed through the plate in the shape of any one of a circle, triangle, polygon.

The method of claim 1, wherein the sensing magnet,
Sensing magnet assembly of the motor is formed to surround at least one side of the plate.

The method of claim 1, wherein the plate,
Sensing magnet assembly of the motor is formed in a size smaller than the diameter of the sensing magnet.

A disk-shaped plate into which a rotation shaft is inserted in the center;
A ring-shaped sensing magnet in which the plate is inserted into a mold and integrally injection-molded with the plate, a main magnet is formed at a position close to an outer circumferential surface, and a sub magnet is formed at a position close to the through hole; And
It includes; serrated concave-convex structure formed on the circumferential surface of the plate,
The sensing magnet assembly of the sensing magnet of the motor is in surface contact with the tooth-shaped uneven structure through an injection process.

The method of claim 7, wherein the plate,
Sensing magnet assembly of the motor formed of a metal material.

The method of claim 7, wherein the uneven structure,
Sensing magnet assembly of the motor is formed at regular intervals on the outer peripheral surface of the plate.

The method of claim 7, wherein the sensing magnet,
Sensing magnet assembly of the motor is formed to surround at least one side of the plate.

The method of claim 7, wherein the plate,
Sensing magnet assembly of the motor is formed in a size smaller than the diameter of the sensing magnet.

The method of claim 7, wherein the plate,
It includes; a plurality of through holes formed at regular intervals adjacent to the outer peripheral surface;
The sensing magnet assembly of the motor is formed to fill the inside of the through hole through the injection process.

13. The method of claim 12,
The ratio of the number of teeth forming the through hole and the concave-convex structure is 1: 2 of the sensing magnet assembly of the motor.